Unfortunately, Switch, most authors follow your 'option A', which means their attributes are often completely wrong, or feature modified quotes or worse, 'requoted quotes' (i.e. quotes which are attributed to those who simply regurgitate what they read as youths).
When trying to 'authenticate' my quotes, many of the sources end up being fairly lengthy, especially if you have to highlight misattributions or modifications of an original quote, so you really can't add it to the tail end of a quote without providing a link to a specific webpage.
I prefer providing the original quote, along with a simple attribution, but offer the sources for anyone interested at the back of the book. Hopefully, that way, I won't continue to contribute to the 'passing off' of worthless information on the net.
I can't tell you the sheer number of 'quote books' which don't authenticate a single quote!
Also, SOL provides no mechanisms for including footnotes, other than at the end of each chapter, and no one is ever going to stop reading, to jump to the end of the chapter, and then search through the entire chapter trying to find where they were. That's simply an unworkable solution. (Sorry for venting, but we've had these 'footnote' discussions before, which never actually found any sort of consensus.)
That said, adding specific footnotes, which link to the Bibliography in my ebooks, makes sense. As it is, I'm adding a footnote "*" to any quotation which differs from what's commonly associated with a particular author, to show that the common claims are disputed.
Also, don't forget that there's a world of difference between how non-fiction and fiction works handle similar situations. Most non-fiction works routinely use end-of-chapter footnotes, so it' makes perfect sense to do the same with quotes, whereas it merely impedes the flow of a story in fiction.
* Again, story about continuing to rant, but I'm hoping for solutions, rather than mere continuances to the existing problems I'm facing.